- ABC-class multi-purpose dry chemical
- Cartridge operated industrial dry chemical fire extinguisher
- K-class kitchen liquid agent
- Clean agent fire extinguisher
- CO2 carbon dioxide fire extinguisher
- H2O pressurized water fire extinguisher
- Water mist fire extinguisher
- Foam agent fire extinguisher
- Class D fire extinguisher
ABC multi purpose dry chemical fire extinguishers are the most common and most utilized of all fire extinguishers in service today. These extinguishers are listed for three classes of fire. Class A, is for ordinary combustibles such as paper, wood and textiles. Class B, is for flammable liquids such as cooking oil, grease, motor oil, gasoline and lamp oil. Class C is for electrical components and circuitry. These extinguishers will extinguish most fires and are the most universal and therefore are recommended and required by code to be installed and maintained in most public facilities and places of employment. This is also the most appropriate extinguisher for use in a typical household.
Cartridge operated industrial dry chemical fire extinguishers are most often installed and maintained near high hazard industrial manufacturing operations. Cartridge operated fire extinguishers are designed to rapidly discharge a large quantity of dry chemical and are capable of extinguishing large fires. These extinguishers are typically more difficult to handle and operate than a normal standard stored pressure unit if you have not been properly trained. The dry chemical in these units is typically the same ABC dry chemical used in the ABC multi purpose units detailed above.
Class K fire extinguishers are manufactured for use in commercial kitchens. The extinguishing agent in the class K extinguisher is a liquid and is rated for restaurant cooking appliance fires. Code requires a class K fire extinguisher to be installed and maintained in all commercial cooking kitchens that produce grease laden vapors.
Clean agent fire extinguishers are common in computer rooms and other areas where the use of dry chemical agents could potentially cause more damage than the fire itself. In the past a product called Halon 1211 was used in these applications but has been phased out because of its ozone depleting properties. The extinguishing agent in these units leaves no residue.
CO2 carbon dioxide fire extinguishers are not as common as they were even ten years ago. Most application that would typically use CO2 have switched to clean agent fire extinguishers as detailed above. CO2 units are high-pressure cylinders and consequently are very heavy. They also require high pressure hydrostatic testing every five years.
H2O pressurized water extinguishers are typically not found in service anymore. They are rated for class A fires only and are not code compliant as a stand-alone extinguisher in most facilities and for most applications. These units hold 2 © gallons of regular tap water and are pressurized with air. Some larger municipalities allow the use of H2O units in some retail stores along with ABC dry chemical fire extinguishers.
Water mist fire extinguishers are typically rated for class A and class C fires. These units discharge a fine mist of distilled water that allows them to be used in areas where electrical hazards exist. The extinguisher is essentially a class A fire extinguisher that can be used near electrically energized components. This would not be an extinguisher installed with the purpose of fighting an electrical class C rated fire.
Foam agent fire extinguishers are typically utilized in industrial applications. The extinguishing agent in these units is AFFF (aqueous film-forming foam). These units do a great job of forming a film over the surface of liquid fuels and preventing re-ignition.
Class D fire extinguishers are manufactured for metals fires. These units are typically found in machine shops that perform milling and machining on combustible metals as well as factories and labs that use combustible metals such as magnesium, titanium, zirconium, sodium, potassium, lithium and zinc.